1. Field of the Invention
This invention relates to counting systems. Specifically, and not by way of limitation, the present invention relates to a system and method for counting people by capturing an image of human heads and faces, analyzing the captured image and counting the people in the image.
2. Description of the Related Art
In many instances, it is imperative to obtain an accurate count of people in a particular area. For example, in marketing analysis, a count of persons is necessary to obtain accurate input data for the analysis. In other instances, for example, in movie theaters, it is beneficial to the owner or movie distributor to know that movie collections are audited and accounted.
Traditional methods of counting people have oftentimes employed people to manually count the persons in a room. However, this method is inaccurate and utilizes expensive manpower. In other situations, methods utilize sensors, such as seat sensors to measure a sitting audience or infrared sensors to measure people moving from one place to another. However, the use of sensors is expensive which often involves extensive modification of an area or seats being observed. In the case of the infrared sensors to measure moving persons, the system requires a narrow passageway and is not useable where a large group of people move together.
Although there are no known prior art teachings of a system or apparatus such as that disclosed herein, a prior art reference that discusses subject matter that bears some relation to matters discussed herein is U.S. Patent Application Publication No. 2006/0062429 to Ramaswamy et al. (Ramaswamy). Ramaswamy discloses a method and apparatus to count people appearing in an image. Ramaswamy discloses reducing objects appearing in a series of images to one or more blobs. For each individual image in a set of images, one or more blobs in the individual image are represented by one or more symbols in a histogram. The symbols are analyzed in the histogram to count the people in the image. Although Ramaswamy discloses some image-based techniques, Ramaswamy merely utilizes a rudimentary image processing method that attempts to distinguish the difference from one image to another. This methodology disclosed a methodology that observes the blobs from different images and applies simple rules to see if these blobs are human. However, Ramaswamy suffers from several disadvantages. Ramaswamy discloses a methodology where the accuracy of the people count is very low due to the application of rudimentary rules on differences within the images. Additionally, Ramaswamy discloses a methodology which uses a human detection rule which assumes the position of a television watching audience and is designed to work only with a television watching audience. Because of the low accuracy of the methodology, user input is required to confirm the audience count. Ramaswamy is also only useable with a small number of people and fails to produce acceptable results for larger audiences. In addition, Ramaswamy requires special illumination or special positioning of a camera.
Accordingly, a system and method are needed which provides an accurate count of people without utilizing expensive hardware or require human intervention. It is an object of the present invention to provide such a method and system.